Fuel proportioning device for internal combustion engines



Jan. 25, 1944. G, GERSON ETAL FUEL PROPORTIONING DEVICE FOR INTERNAL COMBUSTION ENGINES Filed Jan. 3, 1942 o n N s 0 R m Y R6 M m? D H mm mm on 9w VH6 U v 2 M 1 m S .lu WV Y E B m v mm M NF Q. 0% I E. L umwE R Q R 3 w mp c m I .I 6 mm 1 mo 8 s 3 I mw g 2 3 E H ow 6 g Patented Jan. 25, 1944 UNITED STATES 2,339,988 PATENT OFFICE FUEL PROPORTIONING DEVICE FOR INTERNAL COMBUSTION ENGINES Gerhard Gerson, Bar-newline, om, and Dwight B. Byers, Sylvan Lake Village, Micln, assignors to Phillips Petroleum Company, a corporation of Delaware J .Application January 3, 1942, Serial No. 425,564 a 8 Claims. This invention relates to charge forming devices which contemplate the use of hydrocarbon fuels ofwide boiling range in an internal combustion engine.

The desirability of utilizing hydrocarbon fuels of low boiling range (high vapor pressure) has long been recognized. The higher vapor pressure hydrocarbons have good anti-knock properties, andtheir highly volatile nature is con-' ducive both to, easy starting in cold weather and to complete and intimate admixture with air to provide a powerful combustion charge in the engine manifold under all conditions of operation.

Due to the lack of suitable equipment to car- .bureta fuel containing both heavy and light ends,

the marketing of a usable motor fuel has been resolved into two general lines of operation. The first, and by far the most common mode of utilization, has been to remove the more volatile components from so-called natural gasoline (Reid vapor pressure 26-40 pounds per square inch),

leaving a product in the range of 9-12 pounds perv square inch Reid vapor pressure to be marketed as a motor fuel. In removing these light ends, prevention of vapor lock and evaporation loss is accomplished. At the same time, however, the anti-knock value of the fuel is "so lowered that it is necessary to add some nonvolatile anti-knock agent, such as tetraethyl lead, in order to provide a suitable fuel for high compression engines. he resultant'product, commonly known as gasoline motor fuel, is utilizedfin liquid form in the conventional liquid carburetors currently used. J I

The second form of marketing and utilization of volatile motor fuels consists of further refining of the light ends referred to above to obtain propane, butane, and mixtures thereof. These products have been widely marketed as domestic and industrial heating fuels, and more recently have been marketed to some extent as motor fuels. As motorfuels, these products are carbureted from the vapor phase entirely, and are buretors such as the one forming the subject of the present invention.

A principal object of our invention, then, is to provide carbureting means which willhandle a l-i will promote complete 5 Venturi section of the liquid carburetor.

fuel whose constituents may vary widely in the matter of volatility.

A further object is to provide a means whereby both the "normally liquid and the normally gas- & eous constituents of such aforementioned hydroca'rbon fuel may be carbureted simultaneously and with equal facili It is further an object of this invention to proportion the consumption of the various com-- ponents in the same ratio in which they separate from the higher than normal vapor pressure fuel, thus preventing the accumulation of either a liquid or a gaseous residue. which. is unusable.

A still further object is to provide means which separation of the light from the heavy endsin the fuel before entering the carburetor proper, so that there will be no tendency for further separation in the liquid component. By this means vapor lock in the liquid side of the dual carburetor is prevented;

Another object is the provision of a proportion- 'ing means for the liquid and gaseous phases which is responsive to pressure of the gaseous phase flowing to the gas carburetor from the va- :5 porizer throttled in accordance with the change in rate of utilization of the respective phases. A further aim of the invention is to accomplish these results during the maintenance of a substantially constant pressure in the vaporizer.

0 Other advantages and objects will be apparent to those. skilled in the art from a study of the following disclosure.

In the-drawing, numeral I refers generally to a dual carburetor, one side .of which is adapted to accommodate liquid fuel, adapted to gaseous fuel. The gaseous and liquid sides are furnished respectivelywith air inlets 2 and 8, venturis" 4 and 5, and main throttle butterf'ly valves 6 and I, the latter two members heing mounted on a common shaft 8. Fuel proportioning butterfies 9 andlii are mounted on a common shaft Ii and are mounted substantially at right angles with respect to each other, so that 9, for example, will be closed as I0 is open. The two mixing chambers l2 and I3 join in a common riser I, which is in communication with the engine manifold IS. A bell crank 8A is provided .for simultaneous operation of the throttles 6 and 'l in a conventional manner.

a float chamber it, fitted with a conventional float l1 and a needle valve l8 cooperating with a seat [9. On the downstream side of the needle, the liquid fuel nozzle 20 communicates with the The equivalent of this arrangement is also provided for the vapor side of the dual carburetor in which the zero governor 2| serves the same, purpose as does the float control on the liquid side. The zero governor is provided with a flexible diathe other side being The liquid fuel side of the dual carburetor has In the governor, a

attached to the diaphragm water from the the liquid fuel outlet when phragm 22, a

diaphragm is screw 26.- The motion of, the diaphragm is responsively communicated to the valve by a congaseous fuel nozzle 2M the venturi 4 and the communicates between space under diaphragm 22.

Both sides of the with idle fuel .lines, valves and 3| in 23 and 29, and with needle the respective lines for addual carburetor areequipped 'justing the fuel flow therethrough. likewise,

34upon the proportioning butterflies 9 and Ill.

loaded by a tension spring and extends through a guide 38-to the outside of thegovernor body."

Member 31 has formed upon it a rack 38 which" engages a. pinion'4l on the in of the screw 42, and a pressure ,connection leading to the governor interior is provided at 43. The numeral 44 indicates generally a combidlaphragm is resiliently- 36. A member 31 is valve seat 23 and a valve member 24 cooperating therewith. The adjustably loaded by a tension spring 25 and a A valve thrust rod 13 carries a valve member 1l containing ,a resilient seat 12. and cooperating with the nozzle 13 formed on the end of the fuel inlet tube 14.. Pivots in the .valve linkage are providedat 15,16 and 11. The valve member 1| is maintained in alignment with the nozzle 13 by means of the guide web member 18, the valve mem-' her being slidable therein. The upper side of diaphragm plate 311s adjustably loaded by comline 29 when the motor is stopped.

the zero governor 2|.

nation regulator'and vaporizerwith liquid level control. The lower portion of 'this combined device comprises the vaporizer in which is a space for circulation of a heating medium, enclosed by the outer shell 46 and an inner compartment 41, the

the heating medium are providedv respectively at 48 and 49, the contemplated medium being heated engine cooling system, not shown. An outlet for liquid fuel is the upper end of the fuel outlet connection 50 is formed a valve nozzle 53, which may cooperatewith the valve disc 54 to effect closure of in the vaporizer is not high enough to support the float 55. The valve 54 serves to prevent vapor J '65 The line 53 connects the vaporizer outlet Il ii of the liquid fuel side of the float. chamber the-dual carburetors On the upper surface of float 55 is provided atapered valve member 51 with seat 58 in the vapor outlet tube to which-is bolted or otherwise attached a bonthus forming the regulator portion' of the combined regulator-vaporizer unit. The regulator portion is generally'indicated by the numeral 64. The bonnet is provided with a corresponding flange 33, the twollangel latter or which contains the fuel to be vaporized. An inletand an outlet for which cooperates provided at 50. On

the level of liquideing atbonnet '63 is vented I I ization chamber when the tem the inch. by the pression spring 18 and adjusting screw 30. The x to the atmosphere by port A vapor velocity reducing chamber. generally indicated by numeral 82 is placed in the out-, let line 39 whichtleads from the vaporizer 44 to. This chamber is simply a shell structure and may be of any desired shape, such as a cylinder or a rectangular box, for example. Its function is simply to provide a means for reducing the velocity of e vapor stream at l the point where the pressure line 33 is connected for actuation of the butterfly governor 34. Line 84 is in eflect a continuation of the line II, and completes the connection between the vaporizer and the zero governor.

The fuel supply line 35 leadsfrom a source of high pressure fuel not shown, and contains a shut-oil valve 86. This valve serves as a safeguard against los of fuel at unusually high temperatures by excessive vaporization in the vapor! ine is s opp d. which may exceed the shut-off pressure of float engine, and closed while not The merits and advantages of our fuel eyeand dual carburetor will be obvious from following description of its operation. Fuel in liquid form is delivered from the source, not shown, to thepres'sure regulator by means of the supply line 85. The fuel may be motivated y own vapor The pressure of the fuel is reduced to a nominal re, preferably about 1% pounds per square pressure regulator 34. liquid fuel,

phragm oi the butterfly governor 34. The diadisplacedr pressure to a phrasm 3! will' be butterfly i is full open.

position determined by the balancing force of the tension spring 36, and thus the butterflies 9 and ID will assume some definite angular position. If the pressure of the vapor is high, the butterfly 9 will be substantially open an closed; if low, the converse relationship will be established.

Upon cranking of the engine, a suction is established in the manifold. This suction will be imposed on the liquid fuel jet and the vapor fuel jet 21A, and will be imposed on the respective jets in proportion to the relative degree of opening of their respective proportioning butterflies 9 and ID. The subatmospheric pressure in the vapor side of the carburetor will cause. opening of the zero regulator valve which is adjusted to open slightly below atmospheric pressure, thus admitting gaseous fuel to the carburetor. Liquid fuel will meanwhile be also introduced from the float chamber.

In this manner a charge of fuel is introduced to the vapor or liquid side of the carburetor, or

to both sides simultaneously. When disperseda combustible in the air streams in the venturi, mixture for starting the engine is furnished. Manipulations of the main throttles 6 and I will govern the engine speed in the usual manner, since these throttles coact to control the total flow through the respective sides of the carburetor.

With the engine running, flow of fuel is induced through the fuel regulator and vaporizer. Since the temperature of the engine cooling water is at first low, little heat will be supplied to the vaporizer. vaporization will, therefore, be relatively slow, and the liquid level in the vaporizer will build up. Asthefloat 55 rises, the needle 51 moves closer to the seat 58, throttling the pressure to line 59 and hence the pressureto the butterfly governor 35. As a result, the vapor butterfly 9 is urged toward the closed position, and liquid butterfly I0 is opened further. Thus the respective sides of the dual carburetor are made to utilize the vapor and liquid phases of the fuel in proportion to the quantities of each phase formed in the vaporizer.

l0 substantially As the engine and its cooling liquid are warmed,

the vaporizer is influenced accordingly, and progressively greater proportions of the fuel admitted thereto are converted to vapor phase, with a corresponding decrease of the quantity of liquid phase, The vaporizer float will, therefore, be lowered, further opening the vapor outlet (needle 51 recess from seat 58) and causing adjustment of the proportioning butterflies in response to the increased pressure imposed on the butterfly governor.

Once the vaporizer temperature'reaches a running equilibrium, the butterflies which proportion the liquid and vapor phases will assume a deflnite position for a given condition of load, speed and fuel composition. Any change in these conditions will be reflected in the proportioning device, which will adjust itself to compensate for the particular condition imposed. In all cases, the proportioning will be governed by the respective amounts of liquid and vapor existing inthe vaporizer. When the liquid phase prevails, the valve 51 will be entirely closed, there will be no pressure in the butterfly governor, and the vapor butterfly 9 will be entirely closed while the liquid In the case where vapor is predominant,the float will be lowered sufliciently to obtain maximum opening of valve 51, and the pressure in the butterfly governor will be high, The vapor butterfly 9 will, therefore, be fully open and butterfly Ill completely closed. It is noted that the proportioning valves tend to cause consumption of the liquid and gaseous phases in their approximate ratio of separation.

The complete closing of the liquid valve 54 in the bottom of the vaporizer will seldom occur during normal running of the engine. This valve is not for the purpose of proportioning, but is provided in order to prevent complete emptying of the liquid from the vaporizer and insures a reserve of liquid fuel which will always be available for starting. Full opening of valve 51 will be obtained before closure of valve 54, and thus the full range of adjustment of the proportioning butterflies is controlled by the vapor valve 51 and its influence upon pressure in the butterfly governor.

While other devices proposed for dual carburetion of liquid and vapor phases of a fuel may at first appear to be similar to our present disclosure, there are a number of differences of great importance which we wish to point out.

The first is that the particular arrangement of the butterfly governor with respect to the rest of the elements is distinctly advantageous. It is obvious from the drawing and the description of operation that, while the float'in the vaporizer controls indirectly the proportioning, with the aid of the butterfly governor, it does so without varying the pressure on the liquid fuel'entering the carburetor. The regulator 64 maintains a constant pressure on the liquid and vapor in the vaporizer while these components are being withdrawn. Other dual feed devices with which the inventors are familiar use the vaporizer float or equivalent to shut off or throttle the fuel inlet when the liquid level is high, and necessarily this arrangement produces a variation in pressure in the vaporizer, which complicates metering of the liquid portion of the fuel because of the wide range of variable pressures imposed.

By maintaining a constantpressure in the vaporizer, using the float to control the gaseous discharge therefrom tothe gas carburetor and thus effecting proportioning with the aid of a servo mechanism, this disadvantage is elimi-- nated in the present invention. A further advantage resides in arranging the servo mechanism so as to be directly responsive to gaseous phase flowing to the carburetor, which avoids the necessity of a separate line and bleed-ofi and allows more accurate proportioning of the separate phases.

Another point of advantage we wish to demonstrate lies in the particular location and arrangement of the proportioning butterflies, the main throttles and the idling fuel jets with respect to each other.

It is known that the idling fuel jets are best 10- cated-at or outside of the level of the main throttles, so that excessive suction will not be imposed upon thejet when the throttles are practically closed for idling of the engine. What is not common knowledge and we claim as new, is the fact that it makes a material diiierence whether the auxiliary or proportioning butterflies are located nearer or farther from the engine with relation to the main throttles and idling jets.

In the arrangement shown in the accompanying drawing, the best idling condition is obtained. In the event either proportioning butterfly closes fully, air flow will be precluded on that side of the caruburetor.. The same would hold true if the main throttles were placed below instead of above the proportioning butterflies. However, in that case the suction on both idling fuel jets would continue because of the main throttles being slightly open, and fuel would flow from both jets even though the air inlet were blocked on one side by the proportioning butterflies. Thus an extremely rich mixture would be produced and idling of the engine seriously afiected.

In the arrangement we illustrate, suction as well as air flow, are precluded simultaneously when either proportioning butterfly closes, and thus fuel is admitted from .one side only, in proper admixture with air admitted through the same side of the carburetor.

Many deviations in the detail of our carburetor and fuel conditioning system are possible without departing from the teachings of our disclosure. A system of cranks and levers could be substituted for the rack and pinion arrangement shown on the butterfly shaft, for example. Likewise, the zero governor could be separate from the carburetor, the regulator 64 could be separated from the vaporizer, or the volume chamber 82 could be incorporated in the zero governor so long as all the fuel vapor were made to go through it. These deviations are within the scope of this disclosure and would not avoid the same.

Having disclosed fully the structure, operation and advantages of our invention, we claim:

1. A high pressure fuel charge formin device for internal combustion engines comprising means for separating said fuel into liquid and gaseous phases, means for proportioning flow of the respective phases to the engine, a valve for varying the pressure of the gaseous phase flowing to the proportioning means in accordance with a change in the quantity of liquid phase accumulated in the separating means and means responsive to said pressure variation on' the downstream side of said valve operatively connected with the proportioning means tending to cause consumption of said phases in their approximate ratio of separation.

2. A high pressure fuel charge formin device for internal combustion engines comprising means for separating said fuel into liquid and gaseous phases, valve means in the fuel-air inlet to the-engine for proportioning the relative flow of the respective phases, a variable opening valve for throttling the flow of gaseous phase from the separating means to the valve proportioning means in accordance with a change in the quan tity of liquid phase accumulated in the separating means and a pressure responsive device exposed to the pressure of the gaseous phase on the downstream side of the valve operatively connected with said proportioning means tending to cause consumption of said phases in their approximate ratio of separation.

3. A high pressure fuel for internal combustion engines comprising means for separating said fuel into liquid and gaseous phases, valve means in the fuel-air inlet to the engine for proportioning the relative flow of the respective phases, conduits for the respective phases leading from the separating means to the proportioning means, a throttling device in the gaseous phase conduit controlling the pressure of gaseous phase in accordance with a change in the quantity of liquid phase accumu-I lated in the separating mean and a pressure responsive device communicating with the gaseous conduit between the th ottling device and the valve means and operatively connected with the charge forming device valve means tending to cause consumption of said.

phases in their approximate ratio of separation.

4. A fuel proportioning arrangement in an internal combustion engine carburetion system comprising a combination liquid and gaseous phase carburetor, means for separating the fuel into liquid and gaseous phases, variable means for reducing the pressure of gaseous phase flowing from the separating means to the carburetor and pressure responsive means disposed between the variable means and the carburetor for regulating the relative flow of liquid and gaseous phase fuel to the engine.

5. A fuel proportioning arrangement in an internal combustion engine carburetion system comprising means for separating said fuel into liquid and gaseous phases, means for proportioning flow of the respective phases to the engine, a variable opening valve controlled by the accumulation of liquid phase in the separating means for changing the pressure of gaseous phase flowing to the proportioning means-and a pressure responsive device exposed to the pressure of the gaseous phase on the downstream side of the valve and operatively connected with the proportioning means tending to cause consumption of said phases in their approximate ratio of separation.

6. A fuel proportioning arrangement in an internal combustion engine carburetion system comprising a combination liquid and gaseous phase carburetor, means for separating said fuel into liquid and gaseous phases, means for proportioning flow of the respective phases to the engine, a valve for varying the pressure of gaseous phase flowing from the separating means to the carburetor, andv pressure responsive means exposed to the pressure of the gaseous phase on the downstream side of the valve and operatively connected with the proportioning means for causing consumption of said phases in their approximate ratio of separation.

7. A high pressure fuel charge formin device for internal combustion engines comprising means for separating the fuel into liquid and gaseous phases, a fuel-air inlet to the engine for each phase, coacting valves adapted to inversely proportion the flow of fuel through the respective inlets to cause consumption of said phases in their approximate ratio of separation, connected throttle valves adapted to control the overall flow of fuel to the engine through said inlets and'a fuel idling line for each phase connected with the inlets adjacent said throttle valves.

8. A high pressure fuel for internal combustion engines comprising means for separating the fuel into liquid and gaseous phases, a fuel-air inlet to the engine for each phase, coacting valves adapted to inversely proportion the flow of fuel through the respective inlets, connected throttle valves adaptedto control the overall flow of fuel to the engine through said inlets, afuel idling line for each phase connected with the respective inlets adjacent said throttle valves, a valve for controlling the pressure of the gaseous ,phase flowing from the separating means to the carburetor, and pressure of said phases in their approximate ratio of sepcharge forming device 

